curious scanf problem

[skooter]

I've got the following function

void remDuplicate(FI NDFILE filey, int sim, char *filePath)
{
char ans;
numFound++;

printf("Found file %s that is %d%% the same as %s. Delete (Y/N)??\n", filePath, sim, filey.filename) ;
scanf("%c", &ans);

ans = tolower(ans);
if (ans == 'y')
{
printf("Removin g file %s\n", filePath);
unlink(filePath );
numRemoved++;
}
printf("Continu ing.\n");
return;
}

which gets called each time two files are found that are dupilcates. Yet scanf only takes input each second time (1st, 3rd, 5th calls etc..) Any thoughts ehy??

[horace1]

I've got the following function

void remDuplicate(FI NDFILE filey, int sim, char *filePath)
{
char ans;
numFound++;

printf("Found file %s that is %d%% the same as %s. Delete (Y/N)??\n", filePath, sim, filey.filename) ;
scanf("%c", &ans);

ans = tolower(ans);
if (ans == 'y')
{
printf("Removin g file %s\n", filePath);
unlink(filePath );
numRemoved++;
}
printf("Continu ing.\n");
return;
}

which gets called each time two files are found that are dupilcates. Yet scanf only takes input each second time (1st, 3rd, 5th calls etc..) Any thoughts ehy??

scanf() with the conversion specification "%c" returns the next character in the input stream.

so when you enter Y followed by the <enter> key the first scanf() returns Y the next scanf() returns the newline character (put in the stream by the <enter> key).
The thing to do is to put a space before the %c to skip whitespace in the input, e.g.

	scanf(" %c", &ans);

[skooter]

Thanks. Worked a treat!

[ssharish]

well the alterntive for that can be soemthing like this

#include <stdio.h>
#include <string.h>

int main()
{
    int ch;
    
    printf("Please enter [Y/N]\n?");
    ch = getchar();
    
    if('Y' == toupper(ch))
        printf("You eneter \"YES\"");
    else
        printf("You eneter \"NO\"");
    
    getchar();
    return 0;
}

/* my output
Please enter [Y/N]
?Y
You eneter "YES"

Please enter [Y/N]
?n
You eneter "NO"
*/

ssharish